The present invention relates generally to interface devices for allowing humans to interface with computer systems, and more particularly to computer interface devices that allow the user to provide input to graphical environments on computer systems and provide force feedback to the user.
Computer systems are used extensively in many different industries to implement many applications, such as word processing, data management, simulations, games, and other tasks. A computer system typically displays a visual environment to a user on a display screen or other visual output device. Users can interact with the displayed environment to perform functions on the computer, play a game, experience a simulation or "virtual reality" environment, use a computer aided design (CAD) system, browse the World Wide Web, or otherwise influence events or images depicted on the screen.
One visual environment that is particularly common is a graphical user interface (GUI). GUI's present visual images which describe various graphical metaphors for functions of a program or operating system implemented on the computer. Common GUI's include the Windows.RTM. operating system from Microsoft Corporation, the MacOS operating system from Apple Computer, Inc., and X-Windows for Unix operating systems. These interfaces allows a user to graphically select and manipulate functions of the operating system and application programs by using an input interface device. The user typically moves a user-controlled graphical object, such as a cursor or pointer, across a computer screen and onto other displayed graphical objects or predefined screen regions, and then inputs a command to execute a given selection or operation. The objects or regions ("targets") can include, for example, icons, windows, pull-down menus, buttons, and scroll bars. Most GUI's are currently 2-dimensional as displayed on a computer screen; however, three dimensional (3-D) GUI's that present simulated 3-D environments on a 2-D screen can also be provided.
Other programs or environments that may provide user-controlled graphical objects such as a cursor include browsers and other programs displaying graphical "web pages" or other environments offered on the World Wide Web of the Internet, CAD programs, video games, virtual reality simulations, etc. In some graphical computer environments, the user may provide input to control a 3-D "view" of the graphical environment, i.e., the user-controlled graphical "object" can be considered the view displayed on the video screen. The user can manipulate the interface device to move the view, as if moving a camera through which the user is looking. This type of graphical manipulation is common in CAD or 3-D virtual reality applications.
User interaction with and manipulation of the graphical environment such as a GUI is achieved using any of a variety of types of human-computer interface devices that are connected to the computer system controlling the environment. In most systems, the computer updates the environment in response to the user's manipulation of a user-manipulatable physical object ("user object") that is included in the interface device, such as a mouse, joystick, trackball, etc. The computer provides visual and audio feedback of the GUI to the user utilizing the display screen and, typically, audio speakers.
One problem with current implementation of graphical user interfaces is that two distinct actions are typically required of a user to select a function with the GUI: first, the user must accurately guide the cursor to a desired target using a mouse or other device, and second, the user must press a physical button on the mouse or other device while the cursor is displayed over the target. Often, the user will inadvertently press the button while the cursor is not yet at the target, or after the cursor has just overshot the target, resulting in the desired function not being commanded; and the user then has to reposition the cursor and press the button again. Or, when a desired command requires the user to guide the cursor over a target and "double-click" the physical button, the user often misses the desired command since the cursor is off the target at the time of the second "click". Another problem with the current target acquisition and button press commands is that there is no physical feedback to the user confirming that the selection/command process has been successfully completed. A sound, such as a beep, may be used in some cases to confirm a completed command, but this is not very intuitive feedback.